Synthetic surface coverings, such as floor or wall coverings, are well known. Among them, multiple layer coverings usually comprise a lower layer known as “support layer”, and an upper layer known as “wear layer”.
In opposition to other polymeric sheet materials, a floor or wall covering and the different layers of a multiple layer covering have specific properties in terms of flexibility and mechanical resistance.
Surface coverings, and particularly support layers, are usually PVC-based. However due to environmental issues on PVC coverings, alternatives to PVC coverings were developed, for example polyolefin-based surface coverings or surface coverings comprising acid-based polymer(s) being in a neutralized form or not.
However, such surface coverings present several drawbacks, among which poor mechanical properties, especially poor residual indentation.
Furthermore, a polymer-based layer composition comprising a significant amount of fillers, for example a composition comprising a ratio in weight filler/polymer(s) of 1 or more, is difficult to be calendered into a thin sheet and the extractability of the sheet from a hot calender device is a critical issue.
Therefore, for surface coverings comprising at least one layer of a thermoplastic composition comprising a significant amount of fillers, there is a need to improve easiness of production of such surface coverings and to improve their residual indentation properties.